A power transmission component including a hydrodynamic speed variator/torque converter and a lockup clutch is previously known for example from published patent DE 44 33 256 A1. The power transmission mechanism includes an input that is connected to a driving engine with a rotationally fixed connection. This is formed for example by a housing with a wall that runs at least approximately radially. The lockup clutch situated between the latter and the turbine wheel of the speed variator/torque converter includes at least one lamina that is rotationally connected to the turbine wheel, and may be brought into operative connection on the one hand with the housing and on the other hand with an axially movable piston situated between the housing and the turbine wheel, with a hydraulic pressure acting on the piston. A first chamber chargeable with pressurizing agent, which serves to engage the clutch, is situated between the piston and the turbine wheel. Another second chamber chargeable with pressurizing agent, for disengaging the lockup clutch, is provided between the housing wall and the piston. In the first and second chambers chargeable with pressurizing agent, means are provided for reducing the difference in speed of rotation between the lower rotational speed of the flow medium present in the pressure chamber between turbine and piston in acceleration mode with the lockup clutch disengaged or slipping, and the higher rotational speed of the flow medium prevailing in the pressure chamber between piston and housing. This is realized for example by elongating laminae of the lockup clutch radially inward and giving them a slightly shovel-like shape.
To improve the engagement of the lockup clutch, from DE 10 2006 028 557 A1 according to a further development of the means for reducing the rotational speed it is known that the piston element of the actuating mechanism of the lockup clutch, which is connected to the housing by means of a coupling spring device so that it is rotationally fixed but movable in the axial direction, has flow guiding means which influence the rotational speed of a moving fluid between the piston and the turbine wheel, which is intended to cause a more rapid rise in the rotational speed of the moving fluid between the piston and the turbine wheel and thus of the dynamic pressure at the beginning of the engagement of the lockup clutch.
In general, however, for 3-channel versions of the power transmission mechanism when used in vehicles the problem exists of being able to ensure clean and jerk-free regulation of the lockup clutch, due to the hydrodynamic influences of moving fluids.